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1 vote
0 answers
172 views

In Bayesian hierarchical models, what is the difference between an Empirical Bayesian approach to parametrising priors vs using flat hyperpriors

Say I have a simple hierarchical model, where: $y_{g,i} = \beta_g x_{g,i} + e_{g,i}$ where $g$ represents the group, $i$ represents the individual within the group, and $e$ is the error. So the ...
tobmo's user avatar
  • 71
2 votes
0 answers
1k views

Choosing priors for the parameters of Gamma distribution

Suppose that $X_1, X_2, \cdots, X_n$ is a sample drawn from a Gamma distribution with parameter $\alpha$ and $\beta$. Then, the likelihood function can be written as follows: \begin{equation} L(\...
Statistics 's user avatar
1 vote
0 answers
220 views

Hierachical Bayesian modelling using brms: how to insert a prior that reflects cut-offs of Reaction Times distribution?

I am running a hierarchical Bayesian model using brms on reaction times (RTs) of a GoNogo task. The predictors are categorical and include the 3 stimuli/condition that participants observed and the 2 ...
TomC's user avatar
  • 21
0 votes
0 answers
25 views

Data-informed grouping of covariates in Bayesian Hierarchical Modeling?

Is there a way to place a prior on the first stage's betas that allows the second stage groups to be determined from the data? I am working with co-exposures where I am not super confident in how they ...
pakalla's user avatar
  • 13
0 votes
0 answers
70 views

Conjugate Hyperpriors

I heard it was possible to have a Bayesian model with likelihood, prior and hyperprior that has a posterior of closed form, by choosing a conjugate prior and conjugate hyperprior. But I struggle to ...
aru_bdd's user avatar
  • 31
1 vote
0 answers
436 views

Is my Stan model correct? The Jeffreys prior for a heteroscedastic mixed-effects model

I am using rstan to obtain MCMC samples from a heteroscedastic mixed-effects model with different residual variances $\sigma_j^2$ for each experimental condition $j$. One assumption is the Jeffreys ...
Dexter SherloConan's user avatar
1 vote
0 answers
147 views

Prior for Variance Covariance Matrix [closed]

Why in Bayesian Hierarchical Modelling the prior corresponding to a Variance Covariance Matrix is taken to be Inverse Wishart Distribution not Wishart Distribution?
Him's user avatar
  • 41
0 votes
1 answer
102 views

Showing that a posterior is Normal given improper prior

I am having difficulty showing the following problem and I suspect it has something to do with my lack of understanding of the question. The question is this: Suppose we have an improper prior ...
CharlieCornell's user avatar
0 votes
0 answers
73 views

How to parametrize a posterior to use it as a prior in Bayesian statistics?

In my problem, I have two sets of parameters, $\theta_1$ and $\theta_2$, and two datasets $d_1,d_2$ that constrain them with a known likelihood function. There is a certain 'hierarchy' in the model: ...
Ewoud's user avatar
  • 151
5 votes
1 answer
131 views

Behaviour of the marginal in the limit for an infinite sequence of hierarchical priors

Consider the following model: $$y \sim \text{Exponential}(\lambda_0) \\ \lambda_i | \lambda_{i+1} \sim \text{Exponential}(\lambda_i+1) \\ \text{for } i=1,2,\dots,d\\ \lambda_{d+1} = k $$ With an ...
fool's user avatar
  • 2,480
2 votes
0 answers
135 views

When to stop the chain of priors in Bayesian hierarchical models?

From Wkipedia's article on hyperprior: In Bayesian statistics, a hyperprior is a prior distribution on a hyperparameter, that is, on a parameter of a prior distribution. There will be some ...
Aditya's user avatar
  • 183
2 votes
0 answers
42 views

Why do we reparameterize before assigning a hyperprior distribution?

I am studying hierarchical models, and trying to understand a point in the book where they try to decide on a non-informative hyperprior distribution. The hyperparameters is $\alpha$ and $\beta$ for a ...
xxtensionxx's user avatar
1 vote
0 answers
17 views

Group level distribution for positive parameters in Bayesian multilevel models

I am doing a lot of modeling with models that require some parameters to be positive by design. However, I am struggling to figure out which approach works best when I try to use multilevel modeling ...
LiKao's user avatar
  • 2,671
2 votes
1 answer
538 views

How to choose a non-informative or weakly informative hyper priors for my hierarchical bayesian model?

I am learning Bayes on "Applied Bayesian Statistics" by MK Cowles. The chapter about "Bayesian Hierarchical Models" mentioned an example that we estimate a softball player’s ...
CuteCat's user avatar
  • 221
1 vote
1 answer
278 views

For Prior definition in bayesian regression with R package MCMCglmm, how to convey different strength of believe via parameter nu?

I understand the strength of the Prior is set via parameter nu however, I can not find information what nu expresses in statistical terms, e.g. how strong would a prior that is similar to the number ...
Tim M. Schendzielorz's user avatar

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